Formation of gear-wheel teeth.



C. A. PARSONS L S. S. CGOK.`

FQRMATION 0F GEAR WHEEL TEEFH.

APPLICATIGN FILED MAR. 25| 1913.

Patentadep, 26AM@ YSHEETS-SHEET i.

LQQL

C. A. PAHSUN@ :5, S. COOK. FORMATION of GEAR wmv.. mm APPLXCATION FILED HAR. 251913.

Patented sept. 26,1916,

SHEETS-SHEET 2.

mvENTmxp Maf/@a Fmg@ c. A. PARSONS O s. s. COOK.

FORMATION OF GEAR WHEEL TEETH..

APPLICATION FILED MAR. 25| 1913- l l 99,6 l Patentd Sept. 26, 1916.

l V I/yl .u i \\\\\\\\\\\\\\\\\\\\\\\\\\\\\L t VENTOOS y 'V Char/e A. Parsons awa C. A. PARSONS L S. S. COOK. FORMAT-WN 0F GEAR WHEEL EETH,

APELICATIGN HLED MAR. 25, i913:

Eatemedept. 26,1916.

mums-SHEET 4.

fun Mw EFD dan NVP/ m M Cl A. PARSONS & S. S. COOK.

ORMATION 0F GEAR WHEEL TEEN-i.

PPLicATioN man MAnjz. 1913. i L1 @Q a atentedbpt. 26, 1916.

vesmasss Mmmm w c. A. PARSONS @L s. s. 000K.

FORMATION 0F GEAR WHEEL TEETH.

APPLICATION FILED MAR. 25 I9I3.

Patented Sept. 26, 1916.

TSHEETS-SHEET 6.

IHNESSES @mma M660 Q4 I AT T III \i E V5,

C. A. PARSONS & S. S. COOK.

FORMATION OE GEAR WHEEL TEETH.

APPUCATIQN, Hman MAR. 25. 1913.

19E @9,6m Patented sept. 26,1916.

ISHEETS-SHEET 7.

new'

CHARLES ALGRESN FBSQNS, OF NEWCASTLE-UPONTYNE, AND STANLEY SJHTH 006K, F WALLSEND, ENGLAND; SAID (100K SSGNOR TO SAID PARSNS.

FBMTN OF GEAR-WHEEL TEETH.

Specification of Letters atent.

Patented Sept. 26, im@

ppiicaton led March 25, 1913. Serial No. 756,760.

To all who/.t t may concern Be it known that we, CHARLES LGERNON PARsons, K. C. E., of Heeten Works, Newcestle-npon-Tyne, in the county of Northumberland, England, and STANLEY Siii'rir Cook, oil Turoinie lil'vorlis, 1iliallsend-on- Tyne. in the county of lilorthiinherland, England, subjects of the liingo Greet Brit-:iin er"l ireland, have invented certain new and Useful. 'improvements in and .lielating to the Formation oi Gear/Vheel Teeth, of which the 'following is e siecification.

This iniention relates a method of end ineens for forming the teeth ot gear wheels, its object being to eiiirhle such wheels to loe constructed with fi higher degree of accurecy than is obtainable with the processes :it present adopted toi' forming gee-r wheel teeth.

lWhile present machines ifoiin the teeth with e. high order of accuracy zi. still higher degree of accuracy is'desii'iihle to insure the silent opci'iition of such wheels when transmitting hinge powers high speeds, and also to minimize wee.

It is obvious that with the processes :ili'efiily adopted the accuracy of the finished wheel cannot he greater than that of the members ot the purent driving' geni' of the iiiiichine hy which the teeth were formed. Local irregularities iii the driving gear ciiiisc iri'i'giiliii'ities in the teeth of the wheels heine toi'ineih which exactly correspond in :in giiliir )'iosition with those otI the driving geni', and which when such wheels iii'e in operation toi.' the tiiiiisn'iission oiE power will give iisc to periodic vihi'iitions, often of high frequency. :ind thier-etere productive ot noise.

lining' :iilccted h v irregularities :is :ibove de-` sciihid. the gear wheel teeth :ire produced without irregularities or et leest with errors of very much smaller amplitude than those of the parent gear rotating the work.-

The invention also consists in eliminating residual errors in the teeth of ii geel' wheel hy grinding the seme with a hipv extending e considerable length over several teeth, so as to be guided by the average configuration oi' such teeth. '4

The invention further consists in e method of and apparatus for forming the teeth ot' gear wheels as hereinafter described.

Referring non to the accompanying drew ings:-Figiires 1 .und 2 represent inelcvzition and plan respectively :i portion oi' ii gear cuttingmachine adapted to the present invention, the sectional part of F ig. 1 being taken on the line A-ul. oi Fig. 2. Fig 3 is :i View similar to Fig. l. illustrating :i further form of gear cutting machine :iccording to the present invention. Fig. ii. side elevation of :i gear cutting machine cinhodying' two forms ol the present invention. Fig. 5 is a plan of Fig. el. Fig. 6 is :i front view of F A 4. 7 shows details of one oil the worms `with balancing springs Fig. S is :1. side elevation of a modified forni.

in which two worin wheels are employed. Fig. S is i1 plan of Fig. 8. Fig. l() is e. Yfront elevation ot' Fig'. 8. Fig. l1 1s e. detail view showing the iidj'iistinent lliovided foi' worms on their spindles iii the enses in which fixed woi'iiis :iro employed. llig. l2 is zi. side elci'iition ot the foi-in of the invention in which spiii wheels :1i-'e employed to iliivc Ythe work tiihle instead of worms,l and worin wiwi-ls. Fig lf3 is :i plan of Figlll.

ln cari-ying this ini'cifitiion into ei'ect in :i gear cutting machine shown in Figs. l :ind 2, the shaft a, (which will hci'ciniiltei lie referred to iis the drivingi shaft) carries two bevel wheels, Y), c. A bevel wheel. ri, engages with the bevel wheel, L, and is moiintcd on :i sha1 ft, c, extending' across the hed of the machine. rThis shaft :it its tun ther end is provided with e. second bevel wheel, j", engaging" with :i hcvcl wheel, if. on :i vertical spindle. /1 which terminates in :i worm, Engaging with this lutter is u. worin wheel, j. on fi spindle, c, which :it one pei-t of its lengthif'iisformed with :i

modem worm, Z. A. similar arrangement is pio vided in connection `with the second bevel Wheel, c, on the driving shaft, o. The bevel Wheei, o, engages with a bevei Wheci, m, on the vertical shaft, n, which terminates in a. Worin o. The latter engages Vwith a worm wheei, p, on a spindle7 g, which7 similar to the spindle, is, is provided for portion of its length with a worin, 7*. Both the Worms, Z and 7, engage with a Worm wheei7 s, attached to the table` t, on which the work, u, is mounted. The cutter, e, is mounted on a standard, w, and is driven and moved by any suitable means. in this arrangement .the Worms, Z and c" must necesn sarily be of same pitch and be rotated at the sanie speed.

t will oe seen that the rate of movement of the table, t, iseontrolled the tivo wor is, and fr, and any irregulrity in the movement of this table arising trom an irregularity in either of the worms or froml an irregularity in the teeth of the Worm wheel. s, passing in contact with one ot said Worms, is checked by the engagement oi the other worm with the Worin Wheel. it is desirable that the portion of the circumferential iength along the pitchcircle between the points of contact of the wine-fas. Z and f1", with the Worm Wheel, s, should not `oifnipiise exactly Whole number of teeth pitches but should include a traction of a 'tooth pitch so that these points of Contact do not simultaneously correspond to similar parte of the teeth. Alsol it is in generai gueterred to piace the worms so that the oircurnierentiai distance between there is haii e, piteh distance greater vor iess than the haii eircumference of the worm u'heei, so that their engagements are 'in opposite phase, both as regards the period of rotation of the 'work and as regards individual teeth of the driven ifheeh in some eases it may be necessary to provide .springs or sonie Form of ditierential gear to obtain au approximately equal division of the driving force between the Worms, Z, 1', but gcneraiij; the natural eiasticity of the shafts and supporting structure will be' suicient for this purpose. As an example of such spring means see Figs. d to 6, 'where helical springs T areplaced on either side' of the 'Worms Z ando', which are spiined to the shafts ."c

and g, and are allowed a sinaii end piay' upon the shafts k and g, so that they may adjust themselves until a balance of driving force between them is obtained.

`Figs. 4 to 6 also show the application of di'erential gear to balancethe drive. ,in

i this case the cross shaft e is placed at the front ot the machine, and has t ie worms and 0 of opposite hand mounted directly upon it. The shaft e is vaiiowed a sinaii end play, so that the opposite end thrusts of the worms i andgo may adjust themselves. @un

ing to the position ot' the shaft e in this 'form it is necessary to introduce a train of gear wheels, 8,9, 10 and 1l between the oevels and d.. Both the forms' of balaneing shown :may be used together or separately, and may be employed in yconnection with any ot the modifications vherein de-- scribed. Fig. 7 shows details of one of the Worms with springs 7, the worin being provided with a feather i3.

in the arrangement according to Fig. 3, the vertical shafts7 Il, and n, areeaeh provided with two "worms, not shown on the f former, and indicated by the letters '0, y, on the latter. The Worm, o, engages With a worm Wheel., y?, on a spindle, g, provided with a worin, rg. as before. The Worm, y engages with a worm Wheel, e, mounted on aspindie, Z, and also provided with a worm, The worm. '11, engages with a 'Worm x'v-heei, and the worin Q with. a worin Wheel, 3. both of which are attaehedlto the tahie, t. on which the work, u, is mounted. The ivo-nis on the vertical Shaft, h, arie siuiilariy arranged to transmit their rotation to the tabie. f. through two. Worms eny gagging with the worm wheels. s and 3, respeetifeiy. In this modifieation it will be that the rate ot' movement of the table, t, is conti-oiled hy four worms. huurder to break the correspondence of the periodicity oit the irreguiarities in the rate O Tinne-nient or' the table due to irregularities in any of the tour Worms, or in either of the worin wheeis, the latter are preferably 100 made witg 1teeth et different pitch, the 'worms engaging with one worm wheel being, o course. of corresuonding piten. The worms engaging with one worin Wheei will then have to be rotated at a diierent speed 105 to those in engagement with the other Worm wheei, and this difference of speedis suitably provided for in the means connue/ting the drivingv shaft, e, with the spindles on which the worms are mounted. over. the worin wheels1 s and 3 are made of the saine pitch the teeth in these Wheels are iu'ter-nitelufd ciremnerentiaily, this latter hein the arrangement illustrated in Fig. 3.

@niv a single worin drivin"r each of the r, r a 1L worin Wheels, s and 3 may be orovided if hsired,r see Figs. li, to 1? these single .vornis rotating at the same or different speeds according to whether the Worm ivheels 5' and ff are provided with teeth of 120 similar or different pitch. in the .torrn shown in Figs. 8 to 1,0, the teeth of the Wheel s are of iner pitch than the teeth of' the wheei f ust 'iu-o ded with any of the foregoing modiiieations in which the 1vernos are normaily fixed to their vshafts for the purpose off ino-fing the-.munis aiong their artes until nach is aetuaiiy in working Contact with 130 If, hoW- ing ineens of any usual type may messer preferably have single helical teeth, and' trains of helical spur wheels and pinions are carried around to the front of the machine, where they engage with a pair of pinions mounted upon`a common vertical shaft e, these latter pinions being of opposite hand, and the shafts c being allowed 'a certain small longitudinal freedom, a ditierential action takes place, so that these pinions transmit equal forces to the tivo trains, and consequently to the tivo Wheels 17 and 18. *The shaft e in this form corresponds to the shaft e in Fig. 6. ln this manner the angular movement of the Work Y is made to register with the average ccnfiguration of the parent gear, and consequently the errors which would be introduced by any or' the separate drives are eliminated or at least greatly reduced.

it will be seen that the relative position of the member forming the teeth and the wheel on which the teeth are being formed is determined by the general or average configuration of the members or the parent gear. Any small residual errors as may be left in the teeth of the gear Wheel formed in a machine having a multiple drive as above described may be eliminated by grinding the gear teeth with laps of suitable shape, such as are described in my copending application for Letters Patent filed March 25th, 1era, ser. No. *156362.

Having now described our invention what vfe claim as, new and desire to secure by Letters Patent is:-

l. A gear cutting machine comprising in .combination a work table, driven means attached to said table, multiple driving means engaging With said driven means, and means to equalize the driving moments of the different driving means.

i2. A gear cutting machine comprising a table on which 'the work is mounted, a driven member attached to said table, pair of driving members engaging with said driven member and in. opposite phase relation as regards the angular position or their points of engagement with the driven member and also as regards their points of engagement with the individual teeth of said driven member.

3. A gear cutting machine comprising a table on which the Work is mounted, a

driven member attached to said table, a pair of driving members engaging `with said driven member, and in opposite phase relation as regards the angular position of their points of engagement with the driven member and also regards their points of engagement' with the individual teeth of said driven member, and diderential or balance gear to equalize substantially the driving forces of the driving members.

Ll. A gear cutting machine comprising a table on which the Work is mounted, a driven member attached to said table, multiple driving members in engagement with said driven memberand spring means to equalize approximately the driving forces oi the dilierent driving members.

5.' A gear cutting machine comprising in con'lbination a work table, drivenmeans attached to said table, multiple driving means in engagement with said driven means and differential means to equalize the driving forces of the different driving means.

6. A gear cutting machine comprising in combination a Work table, Worm Wheel means attached to said table, a plurality or worms engaging with said worm Wheel means and means between said Worms to equalize the driving forces between them.

7. 'in combination in a gear cutting ma* chine, a work tabla-driven means attached to said table, multiple driving means engaging said driven means, and means between said driving means acting to convey driving force to and equalize the driving forces upon the several driving means.

8. A gear cutting machine comprising in combination a work table, spiral gear means attached to said table, multiple spiral driving means engaging said spiral gear means, and means to equalize the driving forces upon the several spiral driving means.

9. A gear cutting machine comprising in conil'iination a Work table, indexing means attached to said table, and multiple driving means engaging with said indexing means, the points of engagement of said driving means `with said indexing means being located on radii-from the axis of said Work table, said radii being mutually inclined.

l0. A. gear cutting machinevcomprising in combination a work table, indexing means attached to said table, multiple driving means engaging with said indexing means, the points of engagement of said driving means with said indexing means being located on mutually inclined radii from the axis of said work table, and means between said driving means to equalize the driving forces upon them.

11. A gear cutting machine comprising in combination a Work table, a Worm Wheel attached to said table, 'and multiple Worms engaging with said, Worm Wheel, the axes of said worms being mutually inclined.

iic

12. A gea-1* cutting machine comprising in combination a wml; tabe, Worm Wheel a@ L to table, mu'tpe Worms' engngng wh Wolm Wheel, the axes of Smid Worms being 'mutundy incline@ and msnm bmw/een said Worms to 'equaze She driving 'fumes upon them.

Chef

In testmonv whereof, We ax our signa,-

Llres u1 presence of two Witnesses.

CARLES ALGERNDN PARSONS. STANLEY SMTH C0975 'Witnesses CHARLES P. MARTIN, BERTMM H. MATTHEWg 

